A mass spectrometer carried by a satellite performs chemical sensing and analysis of ions in space. The mass spectrometer measures energies of ions and then determines mass-to-charge ratios of the ions based on their measured energies. While in space, an exterior of the satellite acquires varying electrical charge depending on a number of changing space conditions, such as orbital altitude and solar weather events. Conventionally, the mass spectrometer may use the satellite exterior as a “ground” or reference potential for ion energy measurements in the absence of a true earth ground. Ions sampled from outside of the satellite have an apparent ion energy based on a difference between the reference potential of the satellite exterior and a potential of a source of the ions, i.e., where the ions is formed. The apparent ion energy may vary widely, e.g., over several thousand electron volts (eV), as both the ion source and reference potential vary. In some solar weather events, the sun ejects ions with equal velocities despite their different masses. Accurately measuring ion energy across such a wide range of ion energies presents a challenge to conventional space ion energy measurement techniques performed in the mass spectrometer.